Bolt-action firearm construction



May 20, 1941. F. F. BURTON 212421389 BOLT-ACTION FIREARMYCONSTRUCTIONFiled oct. 8, 1958 5 11s 1512 fly/l 11 17 3 '#550 3 o 4#gf/71. 37 363738316532416 53 ZK 275 3o 15 Z7 30 Z7 gag/2 17 Patented May 20, 1941BDLT-ACTION FIREARM CONSTRUCTGN Frank F. Burton, Mount Carmel, Conn.,assignor, by mesne assignments, to Western Cartridge Company, acorporation of Delaware Application October 8, 1938, Serial No. 233,941

8 Claims. (Cl. 42-16) rIhis invention relates to improvements in theconstruction of bolt-action firearms and relates more particularly tothe receiver vconstruction of such firearms.

As will be apparent from the following, considered in conjunction withthe accompanying drawing, the present invention is concerned with aconstruction. and organization of parts wherein the receiver of theboit-action firearm is provided at its rear with a receiver-plug,forward of which the breech-'boit of the rearm operates and which isremovable to permit the installation and the complete withdrawal of thesaid breech-bolt from the said receiver.

One of the objects of the present invention is to provide a simple,reliable and effective receiver construction for lbolt-action firearms,which may be produced at a low cost for manufacture and which willprovide for the ready assembly and disassembly of ythe breech-bolt andreceiver.

Another object of the present invention is to provide a bolt-actionfirearm having a superior construction and arrangement of parts wherebythe receiver is provided with a removable receiver-plug which isnormally removable, but which is automatically prevented from beingremoved when the firearm is cocked.

A further object of the present invention is to provide a superiorbolt-action firearm. construction in which provision is made whereby thefirearm is automatically prevented from being cocked in the event thatthe removable receiverplug is partly unlocked or not fully locked inplace.

With the above and other objects in view, as will appear to thoseskilled in the art from. the present disclosure, this invention includesall features in the said disclosure which are novel over the prior artand which are not claimed in any separate application.

In the accompanying drawing, in which certain modes of carrying out thepresent invention are shown for illustrative purposes:

Fig. 1 is a broken view in side elevation of the receiver and therear-portion of the barrel of a firearm constructed im accordance withthe present invention, together with certain of the parts mounted on orcarried by the said receiver;

Fig. 2 is a view thereof mainly in central vertical-longitudinal sectionand partly in side elevation;

Fig. 3 is a longitudinal sectional view taken on the line 3 3 of Fig. 2,but on a larger scale, and showing the locking-bolt restrained againstmovement into its unlocking position by the rearportion of thefiring-plunger;

Fig. 4 is a view corresponding to Fig. 3, but showing the locking-boltnroved transversely of the receiver into its unlocking position, andshowing the firing-plunger in its forward or fired position to enablethe said locking-bolt to be moved as described;

Fig. 5 is -a transverse sectional View taken on the line 5-5 of Fig. 2,but on a larger scale;

Fig. 6 is a view corresponding to Fig. 5, but showing the looking-boltmoved into its unlocking position;

Fig. 'l is a broken perspective view of the rearportion of the receiver;

Fig. 8 is a top or plan View of the receiver-plug, together with theparts organized therewith; and

Fig. 9 is a perspective View of the locking-bolt, detached.

In the accompanying drawing, there is shown only the receiver and theparts immediately associated therewith, together with a portion of thebarrel, the stock and other structure being omitted for clarity ofillustration, since the invention here invo-lved relates to the receiverand its immediately-associated structure.

In the firearm structure shown, the receiver l5 is of ytubular form withits exterior cylindrically contoured save for certain cuts therein aswill hereinafter appear. rlhe said receiver is formed interiorly with`an axial cylindrically-contoured bolt-receiving passage 16 whichextends throughout the length of the receiver and at its forward endreceives the rear end of a barrel I1 rigidly attached to the forward endof the said receiver in accordance with any approved practice notrequiring detailed description herein.

Fitting into the rear-portion of the bolt-receiving passage I6 in thereceiver i5 is a cylindrically-contoured receiver-plug i8 intermediatethe forward end of which and the rear end of the barrel ll is areciprocating breech-bolt I9 which, generally considered, iscylindrically-contoured and is formed at its rear end with an annularbearing-flange 2B and adjacent its forward end with a similarbearing-flange 2|. Both of the bearing-anges 2!! and 2l, just referredto, have a smooth sliding fit with respect to the surface of thebolt-receiving passage l5 so as to provide support and guidance for thebreechbolt I9 in its reciprocating movement without, however,occasioning any binding action.

The lower portion of the breech-bolt I9 is forimed with a longitudinalpassage 22 in which extends the forward end o-f a spring-guiding pin 23having its rear end provided with a head 24 and seated in aforwardly-opening socket 25 extending longitudinally of thereceiver-plug I8 in axial alignment with the longitudinal passage 22 inthe breech-bolt I3. Encircling the springguiding pin 23 is a helicalbreech-bolt-return spring 26 bearing at its forward end against thefront-end wall of the passage 22 and at its rear end bearing against theforward face of the head 24 of the said spring-guiding pin 23, as isclearly shown in Fig. 2 of the drawing.

Above its longitudinal axis and in parallelism with the longitudinalpassage 22 therein, the breech-bolt I8 is formed with a firing-plungerpassage, generally designated by the reference character 21, and havinga relatively-small-diametered' forward-portion 21a and arelativelylarge-diametered rear-portion 2lb, which latter opens throughthe rear face of the said breechbolt.

Reciprocating in the firing-plunger passage 21 in the breech-bolt I9 isthe forward portion of a reciprocating firing-plunger or strikergenerally designated by the reference character 28 and including acylindrically-contcured bearing-portion 29 located about midway thelength of the said firing-pin and bearing in the rear portion 21h of thefiring-plunger passage 21. Projecting forwardly from the bearing-portion29 of the firingplunger 28 is a firing-pin 30 reciprocating in theforward portion 21a of the firing-plunger passage 21. Projectingrearwardly from the bearing-portion 29 of the said firing-plunger 28 isa shank 3| which is adapted to reciprocate in a bore 32 formed in thereceiver-plug I8 before referred to.

Located intermediate the forward face of the receiver-plug I8 and therear face of the bearing-portion 29 of the firing-plunger 21, is ahelical firing-spring 33 encircling the portion of the shank 3| of thesaid firing-plunger 28 which happens to be located forwardly of thereceiverplug I8 at any given time.

'Ihe shank 3| of the firing-plunger 28 above referred to, is formed asshown in Fig. 2 with a cooking-nose 34 which is engageable by a searnose35 formed at the forward end of a sear 36 having a pair of spaced apartdownwardly-extending actuating-fingers 31-31 respectively formed onopposite sides of the said sear and projecting downwardly along oppositesides of the breech-bolt-return spring 25 for being engaged by a trigger(not shown) of any approved form not herein requiring either descriptionor illustration.

In the particular structure illustrated in the accompanying drawing, thesear 36 is located in a recess 38 formed in the receiver-plug I8. Thesaid sear 3B is mounted in the recess 38 just referred to, upon atransverse pivot-pin 39 and has its rearmost portion yieldingly pressedoutwardly by a Sear-spring 40 seated in a springpocket 4| formed in thereceiver-plug I8 as is clearly shown in Fig. 2.

As thus constructed and arranged the firingplunger 28 is under theconstant forward urge of the firing-spring 33 and is releasablyrestrained, when the gun is cocked, by the Sear-nose 35 of the Sear 36.

Extending diametrically across the rear portion of the receiver-plug I8is a locking-bolt passage 42 which is intersected about midway of itslength by the recess 38 before referred to. The said locking-boltpassage is in general cylindrically contoured to receive with asliding-fit, a

locking-bolt 43 which is also of substantially-cylindrical form andwhich has its respective opposite end-faces 44 and 45 shaped tosubstantially conform to the cylindrical periphery of the receiver i5.At its end adjacent its end-face 44 the locking-bolt 43 projects with asliding-lit into a locking-passage 46 formed in the adjacent wall of thereceiver I5 and terminating at its outer end in a spherically-contouredfingerclearance recess 41 formed in the side ofthe said receiver I5 fora purpose as will hereinafter appear.

At its end adjacent its end-face 45 the lockingbolt 43 extends with asliding-nt into a lookingpassage 48 formed in the side-wall of thereceiver I5 at a point diametrically opposite the locking-passage 46before referred to and in axial alignment therewith as Well as with thelockingbolt passage 42 in the receiver-plug I8.

The locking-bolt 43 above referred to is also formed with an axialspring-pocket 49 which extends from the end-face 45 of the saidlocking-bolt to a point closely adjacent the opposite end-face 44thereof as is clearly indicated in Fig. 5. Housed within thespring-pocket 49 is a helical locking-bolt spring 58 bearing at one endagainst the end-wall or bottom of the spring-pocket 49 and bearing atits other end against a limiting-pin 5| projecting through a diametricalclearance-passage 52 in the said locking-bolt 43 and intersecting thespringpocket 49 therein. The lower end of the stoppin 5| just referredto, extends with a drive-fit into a socket 53 formed in thereceiver-plug I8 at a point below the locking-bolt 43 (Figs. 5 and 6,)The upper end of the stop-pin 5| ts with a drive-fit into a socket 54 inthe portion of the receiver-plug I8 which lies immediately above thelocking-bolt 43.

As thus constructed and arranged, the locking-bolt spring 50 exerts aconstant but yielding effort to maintain the locking-bolt 43 in theposition in which it is indicated most clearly in Figs. 3 and 5 butpermits the said locking-bolt to be moved axially to the limit permittedby the coaction of its clearance-passage 52 and the limiting-pin 5|,into the position in which it is indicated in Figs. 4 and 6.

Slightly inwardly from its end-face 45 the locking-bolt 43 is formedwith an upwardly-opening clearance-notch 55 and with a lowercomplemental clearance-notch 56, both of which have widths, lengthwiseof the locking-bolt 43, slightly exceeding the wall-thickness of thereceiver I5, as will be apparent by reference to Figs. 5 and 6 inparticular. The clearance-notches 55 and 56 have inclined inner andouter walls conforming substantially to the inclination of the adjacentportion of the wall of the receiver I5. The aforesaid clearance-notches55 and 56 in the upper and lower faces respectively of thelocking-bolt'43 are separated from each other in a vertical direction bya contracted neck-portion 51 having a vertical dimension slightly lessthan the similar dimension of a releasing passage 58 leading rearwardlyfrom the lockingpassage 48 in the receiver I5 to the rear edge of thelatter.

For the purpose of guarding against the movement of the locking-bolt 43into its unlocking position when the firing-plunger 28 is cocked, theforward face of the said locking-bolt is provided with a safety-notch 59which is entered on occasion, by the rear end of the firing-plunger 28when the latter is in its cocked position.

For the purpose of making clear some of the advantages of the presentinvention let it be assumed that the parts are in the positions in whichthey are shown in Fig. 1, 2, 3 and 5.

When the locking-bolt 43 is in the position in which it is indicated inthe gures just above referred to, it serves to firmly lock thereceiverplug I8 in place within the rear end of the receiver I by virtueof its extending through the locking-bolt passage 42 and into both ofthe locking-passages 46 and 48 so that a firm seat is provided for thebreech-bolt-return spring 2B and the firing-spring 33 as well as a firmmount for the sear and associated pants. Furthermore, the receiver-plugI8 as thus held in place in the receiver I5, constitutes a rm andreliable abutment for checking the rearward movement of the breech-boltI9 should the same be driven violently rearwardly as for instance by theexplosion of a cartridge.

Should it now be desired for any reason to remove the breech-bolt I9rearwardly from the receiver I5 this may be accomplished only when thefiring-plunger 28 is uncooked so that its rear end is withdrawn from thesafety-notch 59A in the said locking-bolt. Now by first pressing againstthe end-face 44 of the locking-bolt 43 and moving the same cross-Wise ofthe firearm from the position in which it is shown in Figs.

l, 2, 3 and 5 into the position in which it is shown in Figs. 4 and 6,the rearward removal of the receiver-plug I8 will be made possible in amanner as will be more fully described.

When the locking-bolt 43 is moved as just above described to the limitof the movement thereof permitted by the coaction of itsclearance-passage 52 and the limiting-pin 5I, both of thereleasing-notches 55 and 55 of the said locking-bolt will be broughtinto registration with the portions of the wall of the receiver I5respectively lying above and below the releasingpassage 58 in the saidreceiver I5, all as indicated in Figs. 4 and 6. When the locking-bolt 43is moved as just described, its neck-portion 5'I is brought intoregistration with the said releasingpassage 58 so that the entirereceiver-plug I8 together with the locking-bolt 43 and associated partsmay be drawn rearwardly completely out of the rear end of the receiverI5 for either the simultaneous or the subsequent removal of thebreech-bolt I9.

When the receiver-plug I8 is replaced in the receiver I5, it will beobvious that the firingplunger 28 cannot be cocked until the lockingbolt43 -has been fully returned to its lockingposition (Figs. 1, 2, 3 and 5)to register its safety-recess 59 with the path of movement of the rearend of the said ring-plunger.

From the foregoing it will be seen that the construc-tion andarrangement of parts is such that the locking-bolt 43 or its equivalentis automatically held against movement into its unlocking position inthe event that the firing-plunger 28 is in its cocked position, therebyautomatically guarding against the unlocking of the receiverplug I8unti1 such time as the said firing-plunger has been released from itspotentially-dangerous cocked position wherein it might accidentally bereleased and cause the explosion of a cartridge with the consequentviolent ejection not only of the breech-bolt I9 but also of thereceiver-plug I8 and associated parts, which ejection obviously mightoccasion serious injury to a user.

Furthermore by means of the construction and arrangement of parts abovedescribed and illustrated in the accompanying drawing, the locking-bolt43 provides a rugged and reliable retainer for insuring the holding ofthe receiverplug I8 in place in the receiver I5 despite violent blowsand other shocks which might be received by the said receiver-plugduring the use of the rearm of which it forms a part.

'Ihe invention may be carried out in other specic ways than those hereinset forth withoufl'r departing from the spirit and essentialcharacteristics of the invention, and the present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

I claim:

1. A bolt-action firearm-construction including in combination: areceiver having an opening at its rear end; a breech-bolt normally inthe said receiver and removable through the opening in the rear endthereof; a receiver-plug removably mounted in the opening in the rear Aend of the said receiver to the rear of and in line with the path ofwithdrawal of the said breechbolt therefrom and provided with atransversely arranged cylindrically-contoured locking-boltreceivingpassager; a cylindrically-contoured locking-bolt extending through thelocking-bolt-receiving passage in the said receiver-plug and engageablewith the said receiver to releasably hold the said receiver-plug inplace in the said receiver, the said locking-bolt being provided with atransverse limiting-passage; and a limitingpin extending into thelimiting-passage in the said locking-bolt and rigidly carried by thesaid receiver-plug.

2. A bolt-action firearm-construction including in combination: areceiver having an opening at its rear end; a breech-bolt normally inthe said receiver and removable through the opening in the rear endthereof; a receiver-plug removably mounted in the opening in the rearend of the said receiver to the rear of and in line with the path ofwithdrawal of the said breechbolt therefrom and provided with atransversely arranged cylindrically-contoured locking-boltreceivingpassage; a cylindrically-contoured locking-bolt extending through thelocking-bolt-receiving passage in the said receiver-plug and engageablewith the said receiver to releasably hold the receiver-plug in place inthe said receiver, the said locking-bolt being provided with atransverse limiting-passage; a limiting-pin extending into thelimiting-slot in the said locking-bolt and rigidly carried by the saidreceiver-plug; and a spring engageable with the said limiting-pin andthe said locking-bolt and yieldingly urging the latter into itslocking-position.

3. A bolt-action firearm-construction including in combination: areceiver having an opening at its rear end; a breech-bolt normally inthe said receiver and removable therefrom through the opening in therear end thereof; a firing-member associated with the said breechbolt; areceiver-plug removably mounted in the opening in the rear end of thesaid receiver; and a releasable locking-bolt engaging with both the saidreceiver and the said receiver-plug to releasably hold the latter in theformer, the said locking-bolt being provided with a portion interposablein the path of movement of the said firing-member when the saidlocking-bolt is moved out of its locking position to thereby v preventthe cooking of the said firing-member when the said locking-bolt is inother than its locking position.

4. A bolt-action firearm-construction including in combination: areceiver having an opening at its rear end; a breech-bolt normally inthe said receiver and removable therefrom through the opening in therear end thereof; a firing-member associated with the said breechbolt; areceiver-plug removably mounted in the opening in the rear end of thesaid receiver; and a locking-bolt engaging with both the said receiverand the said receiver-plug to releasably hold the latter in the former,the said lockingbolt being' provi-ded with a stop-portion engageablewith the said firing-member when the same is in its cocked position toprevent the said locking-bolt from being moved into its unlockingposition when the said ring-member is in its cocked position.

5. A bolt-action rearm-construction including in combination: a receiverhaving a cylindrical bolt-receiving passage therein; acylindrically-contoured breech-bolt reciprocatable in the bolt-receivingpassage in the said receiver; a cylindrically-contoured receiver-plugremovably installed in the rear end of the bolt-receivingpassage in thesaid receiver; a firing-plunger projecting through the said breech-boltand having a portion extending rearwardly into a recess in saidreceiver-plug; and a locking-bolt carried by the said receiver-plug andengageable with the said receiver to releasably hold the former in thelatter, the said locking-bolt having a portion interposable in the pathof rearward movement of the said firing-plunger when the saidlocking-bolt is in other than its locking position to thereby preventthe said firingplunger from being cocked when the said lockingbolt is inits unlocking-position.

6. A bolt-action iirearm construction including in combination: areceiver having a boltreceiving chamber opening through its rear end; areceiver-plug removably mounted in the rear end of the bolt-receivingchamber in the said receiver; a breech-bolt reciprocable in theboltreceiving chamber of the said receiver at a point forwardly of thesaid receiver-plug and in substantial alignment therewith longitudinallyof the firearm-structure; coupling-means extending between the rear endof the said breech-bolt and the forward end of the said receiver-plugand constructed and arranged to couple the same together againstrelative turning movement but permitting the said breech-bolt to moveaxially relative to the said receiver-plug; and a releasablespring-pressed locking-bolt extending transversely'through the saidreceiver and transversely through the said receiver-plug at pointswithin the lateral boundaries of both thereof.

7. A bolt-action rearm construction including in combination: a receiverhaving a cylindrcally-contoured bolt-receiving chamber opening throughits rear end; a cylindrically-contoured receiver-plug removably mountedin the rear end of the bolt-receiving chamber in the said receiver; acylindrically-contoured breechbolt of substantially the same diameter asthe said receiver-plug and reciprocable in the cylindrically-contouredbolt-receiving chamber of the said receiver at a point forwardly of thesaid receiver-plug and in substantial axial alignment therewith;coupling-means extending between the rear end of the saidcylindrically-contoured breech-bolt and the forward end of the saidcylindrically-contoured receiver-plug and constructed and arranged tocouple the same together against relative turning movement butpermitting the said cylindrically-contoured breech-bolt to move axiallyrelative to the cylindrically-contoured receiver-plug; and a releasablespring-pressed locking-bolt extending transversely through the saidreceiver and transversely through the said cylindrically-contouredreceiver-plug at points within the lateral boundaries of both thereof.

8. A bolt-action firearm-construction including in combination: areceiver having a boltreceiving chamber opening through its rear end; areceiver-plug removably mounted in the rear end of the bolt-receivingchamber in the said receiver; a breech-bolt reciprocable in theboltreceiving chamber of the said receiver at a point forwardly of thesaid receiver-plug and in substantial longitudinal alignment therewith;coupling-means extending between the rear end of the said breech-boltand the forward end of the said receiver-plug and constructed andarranged to couple the same together against relative turning movementbut permitting the said breech-bolt to move axially relative to the saidreceiver-plug; and a releasable spring-pressed locking-bolt carried byand removable with the said receiver-plug and extending substantiallydiametrically through the said receiver and substantially diametricallythrough the said receiver-plug.

FRANK F. BURTON.

